John Kerry releases the 2014 Annual Report on International Religious Freedom at the State Department in Washington DC on Wednesday.
Photograph: Jim Lo Scalzo/EPA

The US secretary of state, John Kerry, has appealed for the release of a Chinese Christian human rights lawyer detained ahead of a planned meeting with a top US envoy in late August.

Kerry made the call for Zhang Kai’s release as the State Department released its annual International Religious Freedom Report, which criticizes Chinese restrictions on Christians, Muslim Uighurs and Tibetan Buddhists. But the department also cited instances where faith-based organizations in the country were able to flourish.

“We have continued to ask questions, we will continue on this, and we hope we will get answers,” Saperstein told a news conference at the launch of the global report.

Among other Asian countries, the report highlighted restrictions on Rohingya Muslims and Christians in Myanmar, and the anti-Muslim sermonizing of hardline Buddhists there.

It cited a failure of the Myanmar government to allow a credible investigation of the January 2014 killings of dozens of Rohingya, who were allegedly killed by security forces in retaliation for the death of a police officer.

Both Myanmar and China have since 1999 been designated by the US as countries of particular concern for engaging in or tolerating severe violations of religious freedom.

On China, Saperstein said there are encouraging signs side by side with deeply discouraging ones.

“During my visit in August, I found that despite widespread continuing government abuses and restrictions, many place of worship were nonetheless full and flourishing. In areas of the country where the government’s hand was lighter, faith-based social service and welfare agencies operate homeless shelters, orphanages, soup kitchens, and made highly positive contributions to the wellbeing of their society,” Saperstein said.

“We’ve urged the Chinese government to use that as a model of what can work nationwide. But far more often, restrictive policies still stifle religious life,” he said.

The report says that religious practice by Uighurs and Tibetans is often equated with separatist or extremist tendencies.